diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gem_cma_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gem_cma_helper.c | 93 |
1 files changed, 82 insertions, 11 deletions
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 33cd51632721..f7ba32bfe39b 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -176,8 +176,8 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv, * * This function frees the backing memory of the CMA GEM object, cleans up the * GEM object state and frees the memory used to store the object itself. - * Drivers using the CMA helpers should set this as their DRM driver's - * ->gem_free_object() callback. + * Drivers using the CMA helpers should set this as their + * &drm_driver.gem_free_object callback. */ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) { @@ -207,7 +207,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); * This aligns the pitch and size arguments to the minimum required. This is * an internal helper that can be wrapped by a driver to account for hardware * with more specific alignment requirements. It should not be used directly - * as the ->dumb_create() callback in a DRM driver. + * as their &drm_driver.dumb_create callback. * * Returns: * 0 on success or a negative error code on failure. @@ -240,7 +240,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create_internal); * This function computes the pitch of the dumb buffer and rounds it up to an * integer number of bytes per pixel. Drivers for hardware that doesn't have * any additional restrictions on the pitch can directly use this function as - * their ->dumb_create() callback. + * their &drm_driver.dumb_create callback. * * For hardware with additional restrictions, drivers can adjust the fields * set up by userspace and pass the IOCTL data along to the @@ -274,7 +274,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); * * This function look up an object by its handle and returns the fake mmap * offset associated with it. Drivers using the CMA helpers should set this - * as their DRM driver's ->dumb_map_offset() callback. + * as their &drm_driver.dumb_map_offset callback. * * Returns: * 0 on success or a negative error code on failure. @@ -358,6 +358,77 @@ int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) } EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); +#ifndef CONFIG_MMU +/** + * drm_gem_cma_get_unmapped_area - propose address for mapping in noMMU cases + * @filp: file object + * @addr: memory address + * @len: buffer size + * @pgoff: page offset + * @flags: memory flags + * + * This function is used in noMMU platforms to propose address mapping + * for a given buffer. + * It's intended to be used as a direct handler for the struct + * &file_operations.get_unmapped_area operation. + * + * Returns: + * mapping address on success or a negative error code on failure. + */ +unsigned long drm_gem_cma_get_unmapped_area(struct file *filp, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + struct drm_gem_cma_object *cma_obj; + struct drm_gem_object *obj = NULL; + struct drm_file *priv = filp->private_data; + struct drm_device *dev = priv->minor->dev; + struct drm_vma_offset_node *node; + + if (drm_device_is_unplugged(dev)) + return -ENODEV; + + drm_vma_offset_lock_lookup(dev->vma_offset_manager); + node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager, + pgoff, + len >> PAGE_SHIFT); + if (likely(node)) { + obj = container_of(node, struct drm_gem_object, vma_node); + /* + * When the object is being freed, after it hits 0-refcnt it + * proceeds to tear down the object. In the process it will + * attempt to remove the VMA offset and so acquire this + * mgr->vm_lock. Therefore if we find an object with a 0-refcnt + * that matches our range, we know it is in the process of being + * destroyed and will be freed as soon as we release the lock - + * so we have to check for the 0-refcnted object and treat it as + * invalid. + */ + if (!kref_get_unless_zero(&obj->refcount)) + obj = NULL; + } + + drm_vma_offset_unlock_lookup(dev->vma_offset_manager); + + if (!obj) + return -EINVAL; + + if (!drm_vma_node_is_allowed(node, priv)) { + drm_gem_object_unreference_unlocked(obj); + return -EACCES; + } + + cma_obj = to_drm_gem_cma_obj(obj); + + drm_gem_object_unreference_unlocked(obj); + + return cma_obj->vaddr ? (unsigned long)cma_obj->vaddr : -EINVAL; +} +EXPORT_SYMBOL_GPL(drm_gem_cma_get_unmapped_area); +#endif + #ifdef CONFIG_DEBUG_FS /** * drm_gem_cma_describe - describe a CMA GEM object for debugfs @@ -391,7 +462,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_describe); * * This function exports a scatter/gather table suitable for PRIME usage by * calling the standard DMA mapping API. Drivers using the CMA helpers should - * set this as their DRM driver's ->gem_prime_get_sg_table() callback. + * set this as their &drm_driver.gem_prime_get_sg_table callback. * * Returns: * A pointer to the scatter/gather table of pinned pages or NULL on failure. @@ -429,8 +500,8 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table); * This function imports a scatter/gather table exported via DMA-BUF by * another driver. Imported buffers must be physically contiguous in memory * (i.e. the scatter/gather table must contain a single entry). Drivers that - * use the CMA helpers should set this as their DRM driver's - * ->gem_prime_import_sg_table() callback. + * use the CMA helpers should set this as their + * &drm_driver.gem_prime_import_sg_table callback. * * Returns: * A pointer to a newly created GEM object or an ERR_PTR-encoded negative @@ -467,7 +538,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); * * This function maps a buffer imported via DRM PRIME into a userspace * process's address space. Drivers that use the CMA helpers should set this - * as their DRM driver's ->gem_prime_mmap() callback. + * as their &drm_driver.gem_prime_mmap callback. * * Returns: * 0 on success or a negative error code on failure. @@ -496,7 +567,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap); * virtual address space. Since the CMA buffers are already mapped into the * kernel virtual address space this simply returns the cached virtual * address. Drivers using the CMA helpers should set this as their DRM - * driver's ->gem_prime_vmap() callback. + * driver's &drm_driver.gem_prime_vmap callback. * * Returns: * The kernel virtual address of the CMA GEM object's backing store. @@ -518,7 +589,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap); * This function removes a buffer exported via DRM PRIME from the kernel's * virtual address space. This is a no-op because CMA buffers cannot be * unmapped from kernel space. Drivers using the CMA helpers should set this - * as their DRM driver's ->gem_prime_vunmap() callback. + * as their &drm_driver.gem_prime_vunmap callback. */ void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr) { |